<!DOCTYPE html>
<html lang="zh-cn">
<head>
	<meta charset="utf-8">
	<title>015-交集选择器.html</title>
	<style>
		/*p.txt{
			color: red;
		}*/
		p.txt.txt{
			color: blue;
		}
	</style>
</head>
<body>
	<div class="txt">div</div>
	<p class="txt">p</p>
	<span class="txt">span</span>
	<p>ddd</p>
</body>
</html>